[ 
https://issues.apache.org/jira/browse/MAPREDUCE-1943?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Mahadev konar updated MAPREDUCE-1943:
-------------------------------------

    Attachment: MAPREDUCE-1521-0.20-yahoo.patch

this patch imposes some limits.

the following are the limits it imposes:

1) The number of counters per group is limited to 40. If the counters increase 
that amount they are dropped silently.
2) The number of counter groups is restricted to 40. Again if the groups are 
more than the limit they are dropped silently.
3) The string size of counter name is restricted to 64 characters.
4) the string size of group name is restricted to 128 characters.
5) The number of block locations returned by a split is restricted to 100, this 
can be changed with a configuration parameter. 
6) limit the reporter.setstatus() string size to 512 characters.

I havent added tests yet. Will upload one shortly. Also, this patch is for 
yahoo 0.20 branch. I will upload one for the trunk shortly.

> Implement limits on per-job JobConf, Counters, StatusReport, Split-Sizes
> ------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-1943
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1943
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>            Reporter: Mahadev konar
>            Assignee: Mahadev konar
>         Attachments: MAPREDUCE-1521-0.20-yahoo.patch
>
>
> We have come across issues in production clusters wherein users abuse 
> counters, statusreport messages and split sizes. One such case was when one 
> of the users had 100 million counters. This leads to jobtracker going out of 
> memory and being unresponsive. In this jira I am proposing to put sane limits 
> on the status report length, the number of counters and the size of block 
> locations returned by the input split. 

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to